‘Fire Sermon,’ by Jamie Quatro

Jamie Quatro made a splash with her 2013 debut, “I Want to Show You More,” a collection of stories intensely focused on two major threats to family: adultery and mortality. At once boldly carnal, spiritual, cerebral and literary, Quatro was hailed as a Flannery O’Connor for our era. With her first novel, “Fire Sermon,” about two academic poets whose strong attraction threatens their marriages and challenges their faith, she’s showing us more, all right — more of the same bracing stuff, though somewhat diffused by length and repetition.

Adultery may be a tale as old as time, but Quatro’s take is freshly urgent, as she grapples with themes of desire, sin, commitment, guilt and renunciation while writing frankly about both marital and extramarital sex. Thorny theological issues and literary allusions to writers ranging from John Updike and Lydia Davis to Sharon Olds and Linda Gregg underpin the novel.

Quatro’s heroine, 45-year-old Maggie, has been married for 23 years to a sweet, accommodating man, though neither her ideal soul mate nor sex partner. When she falls in love with a poet named James whose work strikes a chord, she is tormented by her disloyalty. Jumping back and forth in time between several key dates in the history of her illicit relationship, “Fire Sermon” conveys the all-consuming obsession of forbidden love, whether consummated or not.

Quatro’s short stories were filled with more phone sex than cerebral discussions — and featured wonderful surreal flourishes like the corpse of a woman’s ex-lover taking up residence in her marital bed. There were also small children to complicate the picture. In “Fire Sermon,” the children are off in college, and the intellectual and spiritual rapport between James and Maggie heightens the stakes while weighing down the narrative with often ponderous literary exegeses.

The relationship between Maggie and James begins when she emails him cold because his new poetry collection has given her a “renewed sense of holiness about the world.” She quotes C.S. Lewis to justify having contacted him: “A book sometimes crosses one’s path which is so like the sound of one’s native language in a strange country, it feels almost uncivil not to wave some kind of flag in answer.” James responds in kind, welcoming “a soul of solidarity in this scary time of cheery nihilism.” They bond over a shared longing for “a viable literature of faith.”

Although “Fire Sermon” isn’t linear, we gradually piece together the chronology of Maggie and James’ relationship, which soon progresses to intimate emails signed “Yours — Yours,” phone calls and Skyping. They finally meet at an academic conference, “the day the light changed, the air turned liquid,” Quatro writes.

But their rendezvous are few and far between, as Maggie recognizes early on “that whatever was between us was dangerous, real, and needed to end.” She fights temptation mightily, recalling a sermon in which the minister reminded his parishioners, “God wants your holiness, not your happiness.” She repeatedly declares to James, “Let’s let today be it,” but regrets when he accedes. Renunciation, she notes, fans the flames of desire and leaves “a void inside of you that something else will rush in to fill. Augustine’s God-shaped hole.”

Interwoven with sometimes uncomfortable scenes between Maggie and the two men in her life are sessions with a stern counselor who presses her to examine her past and her motives — repeating verbatim many of the interchanges from her stories. Unsent letters and journal entries addressed to the banished James provide a running tab on Maggie’s emotional state. She tells him that their relationship was “the very best thing” in her life, and that he and God are the only ones with whom she can discuss her complex spiritual struggles — which, admittedly, did cause my eyes to glaze over.

Quatro’s fiery metaphors rage through the pages, as hard to contain as the recent California conflagrations, beginning with epigrams from Buddha’s Fire Sermon and T.S. Eliot’s “The Waste Land.” Maggie’s head warns her heart: “You will watch fire consume everything you care about. You will be left with ash — the proper and only end of any burning.”

As she debates coming clean to her husband she realizes that she is “every cliché in the book.” She imagines “writing all this down” and being told by her agent, “This has been done to death ... I won’t be able to sell this.” Not so, obviously. “Fire Sermon” burns with emotional honesty. Unlike the great adulteresses of fiction, Anna Karenina and Emma Bovary, Quatro’s conflicted heroine is not miserably married; nor is her lover an unworthy boor. The result is an impassioned, deeply moral exploration of devotion and “what’s waiting on the far side of fidelity.”

In addition to The Chronicle, Heller McAlpin reviews books regularly for NPR.org, the Washington Post and the Los Angeles Times, among other publications. Email: books@sfchronicle.com